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Homework Help: 2nd derivative, is my answer correct

  1. Oct 10, 2009 #1
    1. The problem statement, all variables and given/known data
    The position of a particle moving along the x-axis is given by s(t)=7t^2+33. Use difference quotients to find the velocity v(t) and acceleration a(t).

    My textbook says v(t)=s'(t) and a(t)=s''(t). I think I got the answer, but not sure if the velocity should have an x in it. Please reply and let me know.
    2. Relevant equations

    3. The attempt at a solution
  2. jcsd
  3. Oct 10, 2009 #2
    Where did the x come from?
    s(t) = 7t^2 + 33
    so by using the power rule s'(t) = 7*2(t(2-1)) = 14t
  4. Oct 10, 2009 #3
    Sorry I meant t. I was doing a bunch of problems, mostly with x so I got mixed up when I was typing. I meant:

  5. Oct 10, 2009 #4
    [PLAIN]http://calc101.com/Calc101/MSP?MSPStoreID=MSPStore10452429_0&MSPStoreType=image/gif [Broken]

    Yes, you are correct.
    Last edited by a moderator: May 4, 2017
  6. Oct 10, 2009 #5


    Staff: Mentor

    These are correct. Did you get s'(t) and s''(t) using difference quotients?
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